George a



(No Model.)

G. A. COLNON.

` BEAM GALIPERS.

No. 493,683. Patented Mar. 2l, 1893.

UNITED STATES PATENT OFFICE.

GEORGE A. COLNON, OF VASI-IINGTON, DISTRICT OF COLUMBIA.

BEAM-CAL|PERS.`

SPECIFICATION forming part of Letters Patent N0. 493,683, dated March 21, 1893.

Application tiled May 27, 1892. Serial No. 434.533. (No model.)

T0 all whom t 11i/ay concern/.1

Be it known that I, GEORGE A. CoLNoN, a citizen of the United States, residing at Washington, in the District of Columbia, have iuvented certain new and useful Improvements in Beam-Cali pers; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to certain new and useful" improvements in beam calipers and has for its object to produce such a device that shall be extremely light and strong and capable of rapid and accurate adjustment and to provide means for enabling the graduations to be accurately and easily discerned.

To these ends my inventionconsists in the novel construction and arrangement of parts hereinafter fully described and afterward definitely pointed out in the claims, due reference being had to the accompanying drawings forming a part of this specification; wherein:

Figure l is a top plan View of myiinproved device. Fig. 2 is an end View thereof, and Fig. 3 a longitudinal section.

Referring to the drawings the letter A indicates a rod which is longitudinally slotted and has aiixed to one end thereof a jaw B. Within said slotted rod A is set a graduated plate or metallic strip C and secured therein in any suitable manner.

D indicates a movable jaw which is provided With a perforation adapting it to slide over the rod A and is split so as to straddle the graduated strip C and its ends provided with a clamping screw E whereby said jaw may be-locked upon the rod at any point to which it may be adjusted. Secured to the movable jaw D is a standard F carrying at its outer end a frame or casing G within which is pivoted a magnifying glass I'Iin such a manner that said glass may be swung upon its pivot over the graduations marked upon the strip C and thus enable the operator to quickly and accurately note the very smallest graduations necessary to effect a very close measurement. By pivoting the magnifying glass in the casing G, the same is protected from injury, dust and dirt, and it can be readily swung about its pivot tobring it immediately over the graduations.

By the aid of the magnifying glass described I am enabled to effect a liner and more accurate measurement than heretofore has been possible with devices of this nature and am able to read the graduations with more certainty.

What I claim isl. In a caliper square, the combination with a straight rod having a graduated scale thereon and a fixed jaw at one end thereof, of a movable jaw mounted on said rod and provided With a magnifying glass located over the graduated scale, substantially as shown and described and for the purpose specified.

2. In a device of the character described, the combination with the graduated bar and lixed jaw, of the movable jaw and a magnifying glass pivoted to said jaw and adapted to be swung over the graduated bar, substantially as described `and for the purpose specitied.

3. In a device of the character described, the combination of the rod A, the graduated bar C, the fixed jaw B,`the movable jaw D carrying the standard F, the casing G secured to the outer end of said standard and a magnifying glass pivoted within said casing and adapted to be swung over said graduated bar, substantially as shown and described and for the purpose specified.

In testimony whereof I aflix my signature in presence of two witnesses.

GEORGE A. COLNON.

Witnesses:

C. BERNARD WERLE, FRANCK D. J oHNs. 

